Editing Iron (section)

===Deficiency===
{{Main|Iron deficiency}}

Iron deficiency is the most common [[nutritional deficiency]] in the world.<ref name="lpi" /><ref>{{cite journal |author=Centers for Disease Control and Prevention |title=Iron deficiency – United States, 1999–2000 |journal=MMWR |date=2002 |volume=51 |issue=40 |pages=897–99 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5140a1.htm|pmid=12418542}}</ref><ref>{{cite book|first1=Robert C. |last1=Hider |first2=Xiaole|last2=Kong |editor=Astrid Sigel, Helmut Sigel and Roland K.O. Sigel |title=Interrelations between Essential Metal Ions and Human Diseases|series=Metal Ions in Life Sciences|volume=13 |year=2013|publisher=Springer|pages=229–94 |chapter=Chapter 8. Iron: Effect of Overload and Deficiency|doi=10.1007/978-94-007-7500-8_8|pmid=24470094|isbn=978-94-007-7499-5 }}</ref><ref>{{cite book |last1=Dlouhy |first1=Adrienne C. |last2=Outten |first2=Caryn E. |chapter=The Iron Metallome in Eukaryotic Organisms |editor1-first=Lucia|editor1-last=Banci |series=Metal Ions in Life Sciences |volume=12 |title=Metallomics and the Cell |year=2013 |pages=241–78 |publisher=Springer |isbn=978-94-007-5560-4 |doi=10.1007/978-94-007-5561-1_8|pmid=23595675 |pmc=3924584 }} electronic-book {{ISBN|978-94-007-5561-1}}</ref> When loss of iron is not adequately compensated by adequate dietary iron intake, a state of [[latent iron deficiency]] occurs, which over time leads to [[iron-deficiency anemia]] if left untreated, which is characterised by an insufficient number of red blood cells and an insufficient amount of hemoglobin.<ref>{{cite journal |author=CDC Centers for Disease Control and Prevention |title=Recommendations to Prevent and Control Iron Deficiency in the United States |journal=Morbidity and Mortality Weekly Report |date=3 April 1998 |volume=47 |issue=RR3 |page=1 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/00051880.htm |access-date=12 August 2014}}</ref> Children, [[pre-menopausal]] women (women of child-bearing age), and people with poor diet are most susceptible to the disease. Most cases of iron-deficiency anemia are mild, but if not treated can cause problems like fast or irregular heartbeat, complications during pregnancy, and delayed growth in infants and children.<ref>{{cite web|author=Centers for Disease Control and Prevention|title=Iron and Iron Deficiency |url=https://www.cdc.gov/nutrition/everyone/basics/vitamins/iron.html|access-date=12 August 2014}}</ref>

The brain is resistant to acute iron deficiency due to the slow transport of iron through the blood brain barrier.<ref>{{Cite journal |last1=Youdim |first1=M. B. |last2=Ben-Shachar |first2=D. |last3=Yehuda |first3=S. |date=September 1989 |title=Putative biological mechanisms of the effect of iron deficiency on brain biochemistry and behavior |journal=The American Journal of Clinical Nutrition |volume=50 |issue=3 Suppl |pages=607–615; discussion 615–617 |doi=10.1093/ajcn/50.3.607 |issn=0002-9165 |pmid=2773840|doi-access=free }}</ref> Acute fluctuations in iron status (marked by serum ferritin levels) do not reflect brain iron status, but prolonged nutritional iron deficiency is suspected to reduce brain iron concentrations over time.<ref>{{Cite journal |last1=Erikson |first1=K. M. |last2=Pinero |first2=D. J. |last3=Connor |first3=J. R. |last4=Beard |first4=J. L. |date=October 1997 |title=Regional brain iron, ferritin and transferrin concentrations during iron deficiency and iron repletion in developing rats |journal=The Journal of Nutrition |volume=127 |issue=10 |pages=2030–2038 |doi=10.1093/jn/127.10.2030 |issn=0022-3166 |pmid=9311961|doi-access=free }}</ref><ref>{{Cite journal |last1=Unger |first1=Erica L. |last2=Bianco |first2=Laura E. |last3=Jones |first3=Byron C. |last4=Allen |first4=Richard P. |last5=Earley |first5=Christopher J. |date=November 2014 |title=Low brain iron effects and reversibility on striatal dopamine dynamics |journal=Experimental Neurology |language=en |volume=261 |pages=462–468 |doi=10.1016/j.expneurol.2014.06.023 |pmc=4318655 |pmid=24999026}}</ref> In the brain, iron plays a role in oxygen transport, myelin synthesis, mitochondrial respiration, and as a cofactor for neurotransmitter synthesis and metabolism.<ref>{{Cite journal |last1=Ward |first1=Roberta J. |last2=Zucca |first2=Fabio A. |last3=Duyn |first3=Jeff H. |last4=Crichton |first4=Robert R. |last5=Zecca |first5=Luigi |date=October 2014 |title=The role of iron in brain ageing and neurodegenerative disorders |journal=The Lancet. Neurology |volume=13 |issue=10 |pages=1045–1060 |doi=10.1016/S1474-4422(14)70117-6 |issn=1474-4465 |pmc=5672917 |pmid=25231526}}</ref> Animal models of nutritional iron deficiency report biomolecular changes resembling those seen in Parkinson's and Huntington's disease.<ref>{{Cite journal |last1=Pino |first1=Jessica M. V. |last2=da Luz |first2=Marcio H. M. |last3=Antunes |first3=Hanna K. M. |last4=Giampá |first4=Sara Q. de Campos |last5=Martins |first5=Vilma R. |last6=Lee |first6=Kil S. |date=2017-05-17 |title=Iron-Restricted Diet Affects Brain Ferritin Levels, Dopamine Metabolism and Cellular Prion Protein in a Region-Specific Manner |journal=Frontiers in Molecular Neuroscience |volume=10 |pages=145 |doi=10.3389/fnmol.2017.00145 |issn=1662-5099 |pmc=5434142 |pmid=28567002 |doi-access=free }}</ref><ref>{{Cite journal |last1=Beard |first1=John |last2=Erikson |first2=Keith M. |last3=Jones |first3=Byron C. |date=2003-04-01 |title=Neonatal Iron Deficiency Results in Irreversible Changes in Dopamine Function in Rats |journal=The Journal of Nutrition |language=en |volume=133 |issue=4 |pages=1174–1179 |doi=10.1093/jn/133.4.1174 |pmid=12672939 |issn=0022-3166|doi-access=free }}</ref> However, age-related accumulation of iron in the brain has also been linked to the development of Parkinson's.<ref>{{cite journal |author1=Dominic J. Hare |author2=Kay L. Double |title=Iron and dopamine: a toxic couple |journal=Brain |volume=139 |issue=4 |date=April 2016 |pages=1026–1035 |doi=10.1093/brain/aww022|pmid=26962053 |doi-access=free }}</ref>